ABSTRACT A universal influenza vaccine is believed to be possible if conserved regions of influenza are effectively targeted and appropriate immune responses are generated against those targets. The enhanced safety, stability, and accelerated product development generally provided by DNA vaccination make it an appealing approach to develop such a universal influenza vaccine. Unfortunately, immune responses to universal influenza antigens are typically weak and in the past, DNA vaccination of humans has been disappointing. To overcome these and other obstacles to developing an effective, practical, and truly universal influenza vaccine, we intend to deliver our vaccine using a DNA prime / protein boost regimen and employ novel immunogens derived from the following three conserved influenza A antigens: 1) the stem region of hemagglutinin (HA); 2) the matrix 2 protein ectodomain (M2e); and, 3) the nucleoprotein (NP). We believe that together, these antigens will evoke the immunological breadth necessary to protect against a broad range of both seasonal and potential pandemic influenza strains. We will also use a potent DNA adjuvant combination to maximize immunogenicity and to tune the responses toward a Th1 phenotype. Finally, we will utilize a recombinant protein boost to amplify the humoral immune responses and increase their durability. In this Phase I SBIR, we will construct and express our influenza A immunogens and verify their immunogenicity and protective efficacy in mice to determine if the vaccine provides a wide breadth of protection from divergent seasonal and pandemic influenza A strains. If we are successful in this Phase I proof-of-concept study, we will move on to test our vaccine in a macaque challenge model under a Phase II application and begin development on influenza B, and possibly type C, immunogens.